How to fix SIP errors
Softphone.Pro is a SIP client, it is to be configured to use SIP account you got from your PBX provider. In other words, the softphone should communicate with your PBX in order to make and receive calls.
If something goes wrong, PBX shows particular error codes. It's easy for IT professionals but might be confusing for those who are not so close to the topic. This article is to help to understand what's going on.
401 Unauthorized
It's an authorization error. It may be caused by incorrect SIP credentials (server, login, password etc.). With that, sometimes it's enough to double-check your SIP credentials obtained from your provider and to correct mistypes to solve the issue.
To our experience, the most frequent reason is wrong SIP credentials. Another reason for returning this error message from a provider is an attempt to register a VoIP account on multiple devices at the same time as a server might reject multiple registrations. Nevertheless, the person who knows the exact reason is your PBX administrator or VoIP provider, please start from contacting them.
402 Payment Required
This mistake may appear because of payment or billing issues: for example, funds in the account might be insufficient, services required for call processing and correct PBX work are disabled or so.
SIP 402 error is not about payment for the Softphone.Pro use: should the paid period is over, you'll see another notification — «The license key has expired», it will appear in the softphone interface.
403 Forbidden
Usually there are the following common reason for this error:
- Wrong credentials;
- Required username and password have not been provided;
- Wrong international dialing prefix;
- Multiple simultaneous device register attempts;
- SIP account might be deleted or blocked by PBX.
404 Not Found
There is no response from the other side for your PBX's request.
First of all, it worth to check if the dialed number is correct. Besides, the reason might be in fact you are trying to send the traffic with wrong tech prefix: some PBXs don't allow calls if the number starts with plus or some other specific symbols. Finally, there might be config errors on the other side or the other side is not available now, e.g. turned off, overloaded, or on maintenance.
407 Proxy Authentication Required
This error occurs when a proxy server is used between the client and server. In other words, the proxy is unable to authenticate the client so cannot process request correctly.
There is no one-size-fits-all solution as there are multiple possible causes and it might require efforts to identify the exact one; however, you can try do do something on your side.
First of all, check the URL, mistypes can lead to the 407 error. If the issue still persists, check the server configuration files, review the logs, and perhaps debug the scripts, please contact the responsible administrator for help.
408 Request Timeout
The softphone receives no reply from the server or there is no connectivity. The most common reason is changing the network settings or wrong SIP settings. Another possible cause is traffic blocking, please see below.
How to check if there is an issue with internet connectivity: please try to visit a random websites using your browser — if they cannot be found, that's the cause, so please contact your internet provider. By the way, ask along with it if VoIP calls are allowed on its network.
How to check if the cause is the traffic blocking: please try to disable your antivirus program or firewall and see if the issue persists. If it doesn't, that's the case. To see guides for some common programs please click here.
There may be a list of the other possible reasons for 408 error; if the above mentioned hints fail please contact your provider or PBX administrator for solution.
480 Temporarily Unavailable
That means the call cannot reach the destination. The issue is temporary and likely is not on your PBX side.
The possible causes are the following. First, the call is rejected by provider or end device. Second, the call fails due to unreachable or unregistered device or provider. Third, the call might be rejected due to a network's high load.
In the first case please check with the provider. In the second one please check the device or provider registration status. As for the network load, just try again, there are some chances for success.
482 Loop Detected
Incorrect call route or internal PBX error. The best thing to be done in such a situation is to check a routing device settings or to summon someone who is responsible for this.
487 Request Terminated
It usually happens when a pending request is cancelled so the server lets you know about it. But there are might be other possible causes so it would be best to check with your provider. The softphone is no reason to such an issue.
488 Not Acceptable Here
Connection is established but some parameters cannot be enabled or are nor allowed. The changing of SIP trunk settings can likely lead to the fix of the issue. The possible solution is to disable Media encryption in SIP account settings.
500 Internal Server Error
There is a list of reasons, and none is connected with softphone, it's a PBX issue solely.
For example, it might be an internal server error; or no response from database; or the database response is considered wrong; or account has been moved to a remote system; or even an undefined reason. So here we are on shaky ground and guess it would be best to proceed and check with your PBX administrator.
502 Bad Gateway
The system says that some problem in the other network is preventing the request from being processed. This response is sent by a proxy that is acting as a gateway to another network. Please contact a person who is in charge of the network you use. The advice is of little use but still best possible, we think so.
503 Service Unavailable
The issue roots may be in the DNS server that does not reply. It also might be in a firewall or operating system. Finally it might occur when the service you are trying to use is unavailable.
Possible solution: to replace the hostname of your VoIP provider with the server IP address (letters to digits). If the issue occurs from time time and in a random manner, perhaps the problem is not on your side but on the side of your VoIP provider.
603 Decline
What happened: the called party was successfully contacted but cannot or does not want to participate in the call, the softphone is not the cause.
The most common situation is the callee rejected you call; but it is also possible that it is caused by insufficient funds on your account or some other reasons. We guess it would be best to contact your PBX administrator or VoIP provider for the issue solution.